When scanning email to determine if it is spam, several headers may be added to the email message. These are normally not visible in most email clients. You would need to find the option in your email client to show you all headers (perhaps called full headers) to see these for your self.

You can use these headers to construct filters in your email client to filter potential spam to an alternate folder, thus leaving your Inbox free of clutter.

We do not recommend you filter straight to your trash, as there is the small possibility that legitimate email will be marked as spam incorrectly.

Emails that score under 5.0 in SpamAssassin are considered to risky to be marked as spam. These will contain the header that looks like:

X-Spam-Status: No, hits=-4.3 tagged_above=-999.0 required=5.0 tests=BAYES_00, HTML_60_70, HTML_MESSAGE

You can see that this actually scored a negative score, so is very unlikely to be spam.

Emails that score above 5.0 have this header, plus other headers added:

X-Spam-Status: Yes, hits=6.1 tagged_above=-999.0 required=5.0 tests=BAYES_50, FORGED_OUTLOOK_TAGS, HTML_60_70, HTML_IMAGE_ONLY_02, HTML_MESSAGE, HTML_TAG_BALANCE_BODY, LOSE_POUNDS
X-Spam-Level: ******X-Spam-Flag: YES

You can see that the email this came from scored 6.1, failed many more tests and is pretty certain to be spam. In fact, it was trying to sell weight loss drugs.

Note, if you have the appropriate option selected in the Toolkit, the subject line may also be modified to prepend [SPAM].

The easiest tag to use to filter spams is that subject line option. However, if you do not want to modify the subject line of your emails, then we recommend that you use the X-Spam-Flag: YES header.

If you want finer control, you can use the X-Spam-Level tag. The number of asterixes is the integer part of the spam score. By putting different filter rules in the right order you can have fine control over the destiny of spam in your email client.